Constructing LRIS Slit Masks

Constructing LRIS Slit Masks

Slit masks for LRIS are constructed using the autslit software written by Patrick Shopbell. A version of this software package that is current as of July 1998 is maintained in /home/galatea/sco/bin/autoslit3. The basic input for autoslit is an ASCII containing RA,DEC positions and magnitudes. The job of assembling this file comprises most of the work in slit mask production. Some users, if their image sources are from LRIS or P200 (Cosmic), will use Judy Cohen's PALCOORDS code to convert image X,Y measures to RA,DEC for input to autoslit. Other image sources (such as WFPC2) will require that the user derive his/her own astrometric solution for producing the RA,DEC measures required by autoslit. Here I review the steps I have used for my own projects with LRIS:

  1. A redshift survey of WFFC2 galaxies (tailored for BBP).
  2. High redshift galaxy surveys using candidates from LRIS and P200 BRI images
In the list below I denote steps related only to one of the above projects with a (BBP) or (HIGHZ) appendix. The other steps are generally applied in any exercise for slitmask production.

  1. Gathering HST galaxies for LRIS masks. (BBP)
  2. Gathering BRI-selected galaxies for LRIS masks.
  3. Running autoslit to make the mask files.
  4. How to send LRIS slitmask files to Hawaii.
  5. Aligning masks and other info that Roy Gal and I assembled.
  6. Useful LRIS Observing Factoids.


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